Yarn twister



Dec. 9, 1958 Filed Feb. 2, 1954 P. BOILLAT ET AL YARN TWISTER 2 Sheets-Sheet 1 INVENTORE. PHILIPPE Bo/LLAz' EINHA e0 AoHR'E/e.

DBCP 1958 P. BOILLAT ET AL 2,363,277

YARN TWISTER Filed Feb. 2, 1954 2 Sheets-Sheet 2 INVENTORS. PHILIPPE 5011.41:

EE/NHARD IPOHREE.

M, wwsa'w United States Patent rice YARN TWISTER Philippe Boillat and Reinhard Rohrer, Biel, Switzerland, assignors, by mesne assignments, to Heberlein Patent Corporation, New York, N. Y., a corporation of New York Application February 2, 1954, Serial No. 407,725

Claims priority, application Switzerland June 23, 1953 6 Claims. (Cl. 5777.3)

This invention relates to a yarn twister and more eshigh degree of twist such as is useful in certain yarn treating processes. For instance, it will be. appreciated that in temporarily high twisting nylon yarn of 70 deniers up to about 3,000 twists per meter, in order to attain high linear feeding speeds of the yarn, very high rotational speeds of the twister are required. Under such conditions there are presented not only operational problems of undue wear of the twister and breakage of the yarn, but structural difliculties of dynamic balance.

In general, twisters are provided with a longitudinally extending guide or means to guide yarn fed longitudinally along a linear feed axis and with means to trap or entrain yarn at a portion of its feed axis path so as to move it;

angularly about its feed axis and thereby cause it to twist.

It is an object of this invention to provide a twister of improved and simplified construction, economical to manufacture and durable in operation.

Another object is to provide a twister having a light weight twisting element of simplified form facilitating dynamic balance commensurate with high speed rotation.

A further object is to provide a twister adapted to facilitate threading and greatly reduce yarn wear and breakage.

Further and other objects,,features and advantages of the invention will more clearly appear from. the detailed description given below, taken in conjunction with the accompanying drawings illustrating, by way of example,

presently preferred embodiments of the invention, and in which:

Fig. 1 is a longitudinal sectional view taken through the axis of the yarn twister and showing one embodiment of the invention;

Fig. 2 is a similar View showing the outward end of the twister shaft and cooperating twisting element in enlarged scale;

Fig. 3 is a similar view showing a modified form of the device;

Fig. 4 is an end elevation of the device shown in Fig. 3;

Fig. 5 is a view similar to Fig. 2 showing a further modification;

Fig. 6 is a view similar to Fig. 2 showing another modification; and

Fig. 7 is an end elevation of the device shown in Fi 6.

Referring to the drawings and more particularly to Fig. l, the twister shaft is designated as 1 and is supplied with suitable motive means to drive the same at a high speed of the order of 50000-150000 R. P. M. and higher. In the present embodiment this motive means consists of an electric motor designated in general as 2 having a rotor 3 carried by the shaft 1 and a stator fixed to the 2,863,277 Patented Dec. 9, 1958 housing of the motor 2 and consisting of an electrical winding 4 and a core 5. The shaft 1 is provided with end plates 6 and 6 which rotate with said shaft. The housing of motor 2 is provided with bearing blocks 7 and 7 disposed adjacent said end plates 6-6 in which are provided suitable compressed air bearings. In general, such bearings may be constructed and arranged in a manner now to be described. The bearing blocks are provided with axial bores in alignment with the shaft 1 and each of which has rigidly secured therein, as by a press fit, a bearing sleeve such as 8 whose internal diameter is sufiiciently larger than the external diameter of the shaft 1 so as to function in the manner to be hereinafter described. For example, the difference between theinternal diameter of the sleeve 8 and external diameter of the shaft 1 may be of the order of 0.01-0.03 millimeter and will depend upon the degree of air pressure employed. The sleeves such as 8 are each provided with a plurality of relatively small holes such as 9 disposed peripherally thereabout and in communication with a series of annular channels 10 interconnected by a common passage such as 11 in communication with the bore 12 adapted to receive air under pressure from a suitable source connected to the tube such as 13. The air pressure should be of the order of two atmospheres and preferably greater.

The clearance between the shaft 1 and the bearing sleeve 8 is such that the shaft is supported free of contacts with the walls of the sleeves by means of the compressed air and the compressed air passing outwardly passes through cavities such as 14 found on the inner faces of the plates 6 and 6 and outwardly through the space between the end plates 66' and the bearing blocks 7 and 7'. The clearance between end plates 6 and 6' and the respective portions of the bearing blocks 7 and 7' is such that said blocks are held out of contact with said plates by said compressed air.

The shaft 1 is provided with an axial bore 15 extending therethrough from the input or right hand end thereof to the output or left hand end thereof for the passage of yarn traveling in a path along an axis of linear feed. The bore 15 at the output end of the shaft and immediately adjacent thereto is provided with a throat 16 of reduced diameter extending for a limited axial distance. In the present embodiment, for conveniences of construction, the output end of the shaft is provided with a sleeve portion 1a rigidly secured thereto and forming a part thereof. The twisting loop 17 is secured to the end In of said shaft and is constructed and arranged in a manner to be more particularly described with reference to Fig. 2.

The twisting loop 17 is formed of wire having a rounded cross section, preferably circular, in the general configuration of a wicket whose legs are seated in cooperating holes provided in the shaft end In and extending outwardly from the end face thereof to provide opposite side portions such as 18 disposed on respectively opposite sides of the axis of the throat 16 and which are inclined toward each other in a direction outwardly beyond the face of the shaft end 1a. The sides of the loop are provided with shoulders such as 19 smoothly merging with the inwardly disposed portion of the legs 1.8 and from the shoulders 19 the loop continues forwardly terminating in an outer end having a relatively sharp curvature so as to provide a guide portion 20 the center of whose curvature is coaxial with the throat 16; the forward guide portion 20 being disposed substantially in the plane of the shoulders 19 and sides 18. The loop 17 is conveniently held within the cooperating bores in'the shaft end In by a resilient force provided by the wire of the loop 17. In operation the yarn Y is linearly fed through the throat 16 thence outwardly around one leg 18 at the shoulder portion 19 which is offset from the feed axis and spaced outwardly from the end In of the shaft. After passing about the shoulder portion 19- the yarn is guided inwardly by the axially disposed forward portion 20 which serves to position the yarn on the linear feed axis as it leavesthe twister. The gradually outwardly tapering sides of the loop 17 facilitate positioning the yarn in the manner above described and the loop 17' is highly pol ished to provide for ready passage of the yarn there,- over' without damage. Theloop.17 is'symmetrical about the axis of" the, bore 16 to facilitate the passage of yarn about either leg of the loop and also, to insure dynamic balance of the. loop at-highrotativespeeds. The loop. is preferably relatively light in, weight so as to reduce the centrifugal forces resulting from highrotative speeds.

Referring to Figs. 3'. and 4; amodified form of the structure is shown in which corresponding partsbear similar reference characters to. those applied to Fig. 2 exceptfor the addition, of the first hundredth digit prefix. In this embodiment the loop 117, is secured directly to the output end ofthe twister shaft 101 without the intermed y f t e nd. p 1a s. s n n. h s h lower ends of the legs 118 are securedto the shaft 101, in the manner above described, with reference to Fig. 2, and extend outwardly beyond the end of shaft 1 and are inclined toward each other. From the outer ends of the legs 1'18 the loop extends inwardly from opposite sides to form smoothly rounded shoulders such as 119 and the outer end of the loop extends laterally in a, plane perpendicular to the axis of the throat 116 and is provided with a guide portion 128 having a relatively sharp curvature defined by a radius lying substantially on the axis of the bore. .16. The, end portion of the loop. intermediate the guide portion 120 and shoulderssuch as 119 is preferably otfsetin a direction opposite the guide port-ion 120 so as to provide guide channels, such as 11901.

A, further modification is shown, in..Fig. 5 in which corresponding portions, of the device are designated by the same reference characters, employed in Fig, 2 with the addition of the second hundredth digit;- prefix. In this embodiment the shaft 201 is provided with a sleeve 201a serving to securely hold, the lower; ends of the oppositely disposed legs 218. of the loop 217 rigidly to the shaft 201. tions of the loop are designated 219 and 219" and are in the form of wings smoothly merging with the leg portions 218 and being relatively thinin a direction trans-. verse tothedirection of the spacing of the legs 218. An end guide portion 229 serves to smoothly interconnect the outer ends of legs. 218 and is formed and disposed as above pointed out with reference to Fig. 2 If it is desired to twist a very-finesmoothyarn, this embodiment is preferable. In order to. increase the resistance of the passage of the very fine smooth yarn still further, the yarn maybe passed behind both of the laterally spaced guide portions 219 and 219, in a manner indicated in dot and dash lines, in which event after the yarn passes beneath the portion 219 it will pass over the legs 218 thence beneath the portion 219 over the outwardly disposed adjacent portion of loop, 217 and through the guide portion 220 on the underside of loop 217.

A further modification is shown in Figs. 6 an 7 in which the corresponding parts are designated by the same reference numerals as in Fig. 2 with the hundredth digit prefix 3 added. In this embodiment the loop 317 is formed of cast metal integral with the shaft end piece 301a which is provided with a throat 316 and is suitably secured in a recess provided in an enlarged end 30112 of shaft 301. The loop. 317 is provided with diametrically oppositely disposed legs 318 which incline toward each other in an outward direction provided with shoulder portions such as 319 interconnected by a guide portion 329. Said shoulders 319 and outer guide portion 320 are shaped and positioned in a manner similar to that described above with reference toFigs, 3 and 4 (see Fig, 7)

In this embodiment the offset guide pop-- Certain features of the several modified embodiments not specifically described are in general the same as above described in connection with Fig. 2.

Having thus described our invention with particularity with reference to presently preferred embodiments there of it will be obvious to those skilled in the art, after understanding our invention, that various changes and. modifications may be made therein without departing. from the spirit and scope of our invention, and we aim in the appended claims to cover such changes and modi-- fications as fall within the scope of the invention.

What we claim is:

1. In a yarn twister the combination of a rotatable: shaft having an axial bore for the passage of yarn along. an axis of linear feed, said bore being substantially re-- duced in diameter for a limited axial extent immediately adjacent the output end of said shaft to thereby provide a throat, and, a closed loop having side portions disposed on, respectively opposite sides of and spaced out-wardly of said throat and extending from the face of the output end of saidshaft forwardly and having an outer end portion smoothly interconnecting said side portions and providing a yarn guide in axial alignment with. said throat.

2. A yarn twister as set forth in claim- 1 in which said axialyarnv guide, at the outer end of said loop is disposed substantially in the plane of said loop.

3. A yarntwister as set forth in claim 1 in which said axial yarn. guide at, the. outer end of said loop lies in. a plane extending transverse the plane of said loop.

4. A yarn twister having a body portion and a twisting portion extending outwardly beyond the outer end face of said body portion, said body portion having a central hole forthe axial passage of yarn therethrough, said twisting portion having a, side portion spaced radially from said hole at its outer end and disposed beyond the outer end face of said body portion, and said twisting portion having an end portion extending outwardly in an axial direction beyond said side portion and provided with a curvedguideway having a relatively smooth radius of curvature whose center is substantially coincident with: the axis of said hole to thereby provide an axial: guide for said yarn.

5'. In a yarn twister the combination of a rotatable shaft having an axial bore for the passage of yarn along an axis of linear feed and a twisting loop rigidly carried by said shaft and extending outwardly beyond the end of said shaft for rotation therewith, said twisting loop having an offset portion spaced outwardly from the end of said shaft and radially from said bore at its outer end and adapted for the passage of yarn thereabout to thereby guide yarn radially outwardly from its axis of linear feed, said twisting loop also having an outer end in smooth continuity with said offset portion and provided with an axially disposed yarn guide adapted to receive yarn from, saidgofiset portion and hold said yarn in substantial alignment with its axis of linear feed. j

6. In a yarn twister, the combination of a rotatable shaft having an axial bore for the passage of yarn along an axis of linear feed and a closed wire loop of generally wicket formation having rearwardly outwardly inclined legs providing side portions disposed on respectively opposite sides of and. spaced outwardly of said bore and extending from the face of the output end of said shaft forwardly and having an outer end portion smoothly interconnecting said .side portions and providing a yarn guide in axial alignment with said bore, said outwardly inclined legs being disposed in cooperating holes in the.

output end of said shaft and held therein by the resiliency of said Wicket.

(Reterences o follow n pa e) References Cited in the file of this patent 1,752,878 UNITED STATES PATENTS 2359436 135,015 Skinner Ian. 21, 1873 743,707 Fredenburgh Nov. 10, 1903 5 129,454 1,338,600 Underwood Apr. 27, 1920 495,767 1,746,433 Leonard Feb. 11, 1930 6 Ambye Apr. 1, 1930 Kruse Sept. 16, 1941 FOREIGN PATENTS Great Britain July 15, 1919 Germany Apr. 11, 1930 

